The thyroid gland is a small, butterfly-shaped gland that sits at the front of the trachea (throat) just below the larynx. It has two wing-shaped lobes, which are connected by an area in the middle called the isthmus. The posterior part of the thyroid gland contains the four parathyroid glands, which regulates calcium in the blood via PTH (Para-Thyroid-Hormone). The thyroid is responsible for regulating metabolism and the body’s basic metabolic rate (the amount of energy the body uses at rest), such as cardiac output and temperature.
The thyroid hormones affect the rate at which we use carbohydrates and fats, (metabolism) and regulate body temperature, and also have a complex inter-relationship with the reproductive hormones, which can therefore influence fertility and libido as well. As the thyroid hormones regulate many body functions, it can have a widespread effect when it is not functioning properly.
The TSH is one of the hormones measured during a thyroid test, as this is one of the indicators showing if a thyroid is overactive or underactive. If the TSH value on a lab report is high then the problem is an underactive thyroid. The increase in TSH is due to the pituitary sending a signal to the thyroid to convert more T4 to T3, but the thyroid is not responding, making the pituitary increase its signaling and its release of TSH to try to make the thyroid gland respond. The reverse is true for hyperthyroidism, where the TSH is low due to your thyroid making too much thyroid hormone on its own regardless of the signals coming from the pituitary.
The thyroid gland is responsible for producing two main hormones:
· Triiodothyronine, (T3)
· Thyroxine (T4)
Of the two, T3 is four to five times more active than T4. Some of the T4 may also be converted to a non-usable form of T3 called reverse T3, (rT3). Only a small amount of T4 is converted to T3 in the thyroid gland, as the rest of the conversion takes place in the liver and kidneys. If the liver is not functioning optimally this can then also contribute to a lower level of functioning T3.
The signal for your thyroid to make T4 and T3 comes from your pituitary gland via the hypothalamus.
· The hypothalamus sends a signal of TRH (Thyrotropin) to the pituitary gland
· The pituitary responds to the TRH signal and sends its own signal of TSH (Thyroid Stimulating Hormone) to the thyroid gland to make more T4 and T3.
There are six causes of hypothyroidism:
1. Primary hypothyroidism, which means the thyroid is not responding to the TSH signals from the pituitary to convert more T4 to T3. 95% of hypothyroid cases are caused by primary hypothyroidism, meaning the problem is in the thyroid.
One of the most common hypothyroid problems is Hashimoto’s thyroiditis, which is an autoimmune disease, meaning the body is attacking itself. Nobody really understands why the body attacks itself, but it is believed to be multifactorial. The antibodies that attack your thyroid are called thyroperoxidase, (TPO) and antithyroglobulin. When these antibodies are high it often calls for a different treatment protocol to lower the immune response and help stop the attack on the thyroid.
2. Secondary hypothyroidism, also called central hypothyroidism, is the failure of the pituitary gland resulting in low TSH output.
3. Tertiary hypothyroidism is the failure of the hypothalamus to release TRH to signal the pituitary to release TSH for the thyroid.
4. The thyroid fails to convert T4 to T3.
5. Receptor uptake failure, also referred to as thyroid resistance, which is similar to Type 2 diabetes in that there is a resistance of the receptors to cooperate and do their job.
6. Adrenal insufficiency, which leads to lower cortisol production which in turn affects the thyroid function.
Many factors are associated with an impaired thyroid function, such as high stress, illness, heavy metal toxicity, impaired liver function, poor nutrition, drug interactions, low calorie diets, fasting and old age. Estrogen dominance or progesterone deficiency, as well as low DHEA, can also contribute to hypothyroidism as well as a high or low cortisol.
Some causes of hypothyroidism include birth control pill, pregnancy, menopause, poor liver function, and nutritional deficiencies in zinc, selenium, copper, magnesium, manganese, vitamins A, B2, B3, B6 and B12, Vit C and E. Toxic metal burden, injury to the neck and misalignment of cervical vertebrae, food sensitivities and candida can also contribute to hypothyroidism. Medications such as beta blockers, (Amiodarone, Dilantin), and other drugs can also contribute. Cigarette smoke also plays a role, as it contains cadmium and thiocyanate which increase autoimmune disease and decrease T3.
Another cause of hypothyroidism is due to excess cortisol that is released under physical or mental stress, which will cause less conversion of T4 to T3. When the body is experiencing physical or mental stress, the cortisol level increases, as this is the stress hormone in the body allowing you to “flee the tiger”. When the cortisol levels increase the body responds with an increase in TSH but less conversion of T4 to T3. (This data comes from new research, but it is also believed that the increase in cortisol causes low TSH and therefore less T3 and T4. More research is needed on this topic.)
Adrenal fatigue also contributes to hypothyroidism. Adrenal fatigue usually develops after a few years of constant stress, trauma, poor lifestyle or dietary habits. When the adrenal glands get weak, the body will start to break down, in a process called catabolism. Because the thyroid controls the metabolic rate, it will slow down this process by being underactive. There are easy saliva tests where you collect saliva in test tubes four times in one day that can show what your cortisol level is throughout the day. If you have low cortisol you most likely have adrenal fatigue, which may then be related to your lower thyroid function.
Symptoms of Hypothyroidism:
· Weight gain
· Sensitivity to cold
· Dry skin
· Thinning hair, brittle hair and hair loss
· Thin and brittle nails with transverse grooves
· Slower heart rate
· Increased cholesterol, LDL and Triglycerides and low HDL
· Sleep apnea
· Low blood pressure
· Muscle weakness
· Slow reflexes, particularly Achilles tendon reflex
· Low stomach acid
· Mineral deficiencies
· Poor zinc absorption
· Memory problems
Treatments for Hypothyroid:
In order for your thyroid to function properly it needs nutrition, such as iodine, selenium, zinc, magnesium, manganese, Vit. A, C and E as well as vitamin B2, B3, B6, B12. An easy way to get enough iodine is to use small amounts of iodized salt on your foods, and eating just two or three Brazil nuts daily, which will give you enough selenium. Other foods rich in selenium include tuna, halibut, sardines, ham, shrimp, macaroni, steak, turkey, beef liver and eggs. You can also take a 200 mcg supplement of selenium per day. Eating sea vegetables such as kelp, dulse, nori, and wakame are good sources of iodine, as are beans, nuts, spinach, summer squash, onions, turnip, garlic, dairy, eggs and table salt.
Excess iodine is excreted in urine, bile, sweat and tears and there are no cases of people having experienced a toxic effect from eating too many foods containing iodine. Warming spices which can be helpful include cinnamon, ginger, cayenne and fennel.
Many herbal supplements can also stimulate or hinder your thyroid. Herbs that are often used in hypothyroidism usually cause an increase in T3. Examples of stimulating herbs are ashwaganda, guggul, ginseng, olea (Oliver leaf) and bacopa.
Hypothyroid is usually treated with either Levothyroxine or Desiccated Thyroid Extract such as Nature-Throid or Armour thyroid. The difference between synthetic and desiccated thyroid medications are that Levothyroxine supplies only T4, whereas Nature-Throid and Armour thyroid provides both T4 and T3, which can be helpful if the conversion from T4 to T3 is not optimal.
If you think you may have a thyroid problem, it’s easy to check your thyroid status with a simple blood test. Consult your physician to discuss your symptoms and to evaluate your thyroid function.
When the thyroid is hyperactive it is called hyperthyroidism, which means the body is producing too many hormones. There is an increase in what is called Thyroid Stimulating Immunoglobulins, (TSI), which are antibodies to the TSH receptors located on the thyroid gland. As these immunoglobulins bind to the TSH receptors it will stimulate the thyroid gland to release T4 and T3. Hyperthyroidism can be caused by an overactive thyroid gland or cancer, as well as by taking too much thyroid medication.
As the thyroid gland is the only gland that takes up iodine, a test called Radioactive Iodine Uptake test can be performed and can help determine the cause of the overactive thyroid.
Symptoms of Hyperthyroidism:
· Sudden weight loss
· Enlarged thyroid (goiter)
· Rapid heartbeat
· Brittle hair
· Difficulty sleeping
· Fast pulse
· Heart palpitations
· Enlarged heart
· Increased risk of cardiovascular disease
· Soft nails
· Clubbing of fingertips
· Over activity
· Panic attacks
· Mood swings
· Frequent bowel movements
· Zinc and calcium deficiency
· Protruding eyeballs, (Grave’s Opthalmopathy)
Treatments for Hyperthyroidism:
Many times hyperthyroid patients are treated with radioactive iodine to calm down the overactive thyroid, which can then lead to reduced function resulting in hypothyroidism, i.e. an underactive thyroid.
Herbs that hinder your thyroid and are typically used in hyperthyroidism to reduce thyroid activity are Lycopus virginicus and Moringa (horseradish tree).
If you think you may be suffering from a thyroid condition, it is always best to be evaluated by a doctor.
The information contained on this site is for educational purposes only. These statements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease. Please discuss all your medical issues with your doctor.